The present invention relates to a device for locking a moving part that is to be secured of a motor vehicle.
A device of this type is described in document DE-OS 1 428 579 and is used to secure motor vehicle parts, such as sliding doors, tilting seats or tilting back rests, for which there is a risk of these moving unintentionally during the operation of braking or starting the corresponding vehicle or when negotiating a bend. The known device essentially comprises a pivoting securing part which, when the vehicle motion varies, pivots under the effect of the force due to the mass and comes into engagement with a second securing part.
This known device has, among others, the drawback that the parts that are to be secured are generally locked together only when the force acting on the securing part as a result of the variation in motion acts on this part (or, as the case may be, on a mass connected to the securing part) in an entirely defined predetermined direction. The known device may admittedly be shaped in such a way as to secure the part that is to be secured, for example, against motion due to a head-on collision or against motion due to a side impact, but the known device does not allow the securing part to be activated not only in the event of a head-on collision but also in the event of a side impact. When motor vehicles roll, in particular, acceleration forces may, however, come from different directions which means that the known device is generally not able to sufficiently secure motor vehicle parts that need to be secured against the corresponding unintentional motions encountered when the corresponding vehicle collides with an obstacle.
Document DE-B 20 23 859 describes a device for locking a motor vehicle fastener, which comprises a handle guide fixed to the respective door of the motor vehicle, in which the door handle which has a handle stem projecting into the door is mounted so that it can pivot. To prevent the door from opening through pivoting of the door handle in the event of a side impact, the known device has, by way of securing part, a two-arm lever, the first arm of which takes an additional mass, and the second arm of which rests against the handle stem connected to the handle. In the event of a side impact, the additional mass exerts an inertia force multiplied according to the lever arms, which is oriented away from the inertia force acting on the handle, and therefore prevents unintentional opening.
In this known device, the additional masses needed are normally of the order of magnitude of the mass of the handle so as to compensate for the force of inertia acting on the handle in the event of a corresponding impact. Furthermore, this known device immobilizes the door handle only when the acceleration forces have corresponding components of force in the direction of opening. The acceleration forces that present themselves in the event of the vehicle being rolled do not therefore generally cause any pivoting of the securing part, which means that in such instances unintentional opening of the vehicle door cannot be precluded.
This last comment is finally also true of the device described in document DE 44 18 317 C2 for locking a motor vehicle fastener. This known device also comprises, by way of securing part, a two-arm lever of which the first arm however takes only a relatively small additional mass. The second arm of the lever engages, when the additional mass moves in the direction of opening, laterally in a slot-shaped cavity of the shaft of the handle and therefore prevents its outward displacement.
Taking as a basis document DE 44 18 317 C2, the object of the invention is a device which is manufactured in a simple and unbulky way, and which reliably prevents unintentional opening of the vehicle door even when acceleration forces coming from different directions are acting on the part that is to be secured.
The invention relies mainly on the idea that the securing part, which needs to engage in the slot-shaped cavity of the part that is to be secured, is controlled by a spherically shaped control element, the control element pressing on a guide via control surfaces of domed or frustoconical shape and being held in its normal position by means of a spring.
The securing part, which comprises an immobilizing pin tailored to the cavity of the part that is to be secured, may be shaped in such a way as to be able to perform a pivoting or translational movement.